1. Field of the Invention
The present invention relates to the field of pipe connections. More particularly, the present invention relates to the field of welded pipe connections normally useful in the oil and gas production, refining and transportation industries and flanged pipe connections normally useful in the chemical plant industry.
2. Background of the Related Art
Corrosion barriers are useful in conjunction with pipes by joining pipes whose interior regions are coated with protective materials, such as thin polymer based coatings or cement based liners, which form a protective barrier between the pipe material and the materials passing through the pipe. In some instances, as in highly corrosive environments, the protective barrier may be constructed of a tubular PTFE or other polymer based material.
In the oil and gas transportation industry, the most common method of connecting individual lengths of pipe is by welding the ends together. Welding of the pipe ends presents several pipe material protection problems. The Cylindrical Corrosion Barrier For Pipe Connections, U.S. Pat. No. 5,547,228 and U.S. Pat. No. 5,566,984 provide for methods of solving those pipe material protection problems.
Corrosion of the pipe material caused by anaerobic and/or aerobic bacteria is another common problem within the oil and gas industries. It is common practice in the oil and gas industry to enhance the productivity of their oil and gas gathering operations to inject fluids into the ground through wells placed near the perimeter of an existing, or new, oil or gas field. The purpose of this injection is to increase the pressure of the oil or gas at the well head thereby increasing the amount of oil or gas that is available for capture by the gathering system. The most common fluid injected into these wells would be water with a high saline content. Some of the common types of this type of water would be known as brine or sea water. Other types of fluids may be injected for this purpose. Some may have other types of ingredients mixed with the water such as specially designed polymers.
When the oil and/or gas is brought to the surface by using this injection method, some of the injection fluid is mixed with the oil and gas. This fluid is separated from the oil and gas before transporting the oil and gas to its refining destination. This separated material is often contaminated with by-products of the oil and gas and other sub strata minerals, chemicals and materials that have dissolved and blended with the solution. It is also a normal procedure for the oil and gas industry to recover these fluids and re-inject these materials into the injection well formation. This eliminates the costly and hazardous method of treating this fluid for environmental concerns.
Often the fluids that are injected into these wells contain contaminates such as aerobic and anaerobic bacteria. These contaminants are very harmful to the unprotected areas of steel pipelines. The Cylindrical Corrosion Barrier as disclosed in the above referenced patents may effectively seal this unprotected area, as a result of the welding process, when it is installed. The product is designed to provide long term corrosion protection by preventing any fluid from penetrating the sealing design of the product. However, this protective design might not effectively protect the exposed metal surface of the pipe from attack by bacteria, specifically anaerobic bacteria, since the design is predicated upon the quick deoxygenation of the material penetrating the sealing system. Since anaerobic bacteria can survive in low oxygen or oxygen-depleted environments, there still exists a need for an apparatus to eliminate these bacterial elements before they can penetrate to the unprotected areas of the pipe. Furthermore, there exists a need for a corrosion barrier with antibacterial protection which also solves the problems of welding pipes joints.